Problem: Simplify the following expression: $t = \dfrac{3}{3a - 1} \div \dfrac{2}{9a}$
Explanation: Dividing by an expression is the same as multiplying by its inverse. $t = \dfrac{3}{3a - 1} \times \dfrac{9a}{2}$ When multiplying fractions, we multiply the numerators and the denominators. $t = \dfrac{ 3 \times 9a } { (3a - 1) \times 2}$ $t = \dfrac{27a}{6a - 2}$